Driving device



OC. 5, 1937. V,'E PRATT DRIVING DEVICE Filed March 11, 1936 2 sheets-sham 1 x .Il lll. I..

lNVENTOR Vmmvx E. PMU* ATTORNEY Oct.A 5, 1937. v. E. PRATT 2,094,659

DRIVING DEVICE Filed March 1l, 1936 2 Sheets-Sheet 2 llll lNVENTOR VLjRNsz/x E. Pzmrr ILH- BWM ATTORNEY Patentedocf. s, 1937 PATENT OFFICE DRIVING nEvIo Verneur E. Pratt, Stamford, Conn., assigner to Harry Snellenburg, Jr., New York, N. Y.. Verneur E. Pratt, Stamford, Conn., and James H. Rand, Jr., New York, N. Y., as trustees Application March 11, 1936, Serial No. 68,208

10 Claims. (Cl. '2L-354) 'i'his invention relates to improvements in driving devices.

l An object of the invention is to provide means by which two shafts may be alternately or selectively driven in opposite directions from a single drive shaft.

Another object is to provide a device of the above character in which the shift from one driven shaft to the other is eiected automatically upon reversal of torque applied to the drive shaft.

A further object is to provide a device of the character described in which the shift is eiected quickly and substantially without lost motion.

Another object is to provide a device of the above character in which a two-speed drive is provided in either direction.

A further purpose is to provide a device particularly adapted to driving films in projectors and the like.

A still further object is to provide a device of the above character including torque-limiting meansby which protection is provided against injury to films or other delicate elements being driven.

Other objects and advantages of the invention will appear during the course of the following description in connection with the accompanying drawings, in which,`

Fig. 1 is a view partially in section of the device embodied in a projecting device adapted to be driven thereby.

Fig. 2 is a. front view4 of the device in one driving position with the front carrier plate removed.

Fig. 3 is a similar view of the device in the opposite directional driving position.

Fig. 4 is a. fragmental sectional view showing the gear shifted into low speed driving position. Fig. 5 is a front view of a modified form of the invention. 40 Fig. 6 is a side view of the same partly in .f section.

` Fig. 'I is an end view of a typical driving hub.

Referring to Fig. 1, the numeral I0 indicates the casing of a reading or reference projector of application, Serial Number 68,204.

It will be understood, however, that the present /sinvention is not limited to use with the above y projector, which is described herein to illustrate 50 `a typical application of the driving device.

A film magazine II is mounted on locating pins I2 securedto the wall I3 of the casing and is held thereon by a spring-pressed plunger I4 carried by a'hinged side plate I5 provided with a 55 nach le.

the type iully described and claimed in copending An upper illm reel Il has a hollow internally splined inner pivot I8 journalled in the wall I9 of the magazine II and an outer pivot 20 journalled in a spring plate 2| held in place by the magazine closure plate 22. A central pin 23 serves to locate the spring plate- 2| vertically. A lower film reel 24 similar to reel Il similarly has secured therein a hollow internally splined inner pivot 25 journalled in the magazine wall I9 and an outer pivot 26 journalled in the spring plate 2|.

Wound on the reels Il and 24 is a film V2l terminally secured to the reels by clamping segments 28 and 29, respectively. 'Ihe lm 2l in its passage from reel to reel runs over guide rollers 30 and 3I, and spans a light aperture 32 in the magazine I I in line with a projection lens 33.

Bosses 34 and 35 on the wall I3 have threaded therein screws 36 and 3l rotatably supporting retaining upper and lower driving hubs generally denoted by the numerals 38 and 39, and carrying pinions 40 and 4I as shown in Figures l, 2 and 3. As the two driving hubs are identical in structure, the upper hub 38 is partially broken away in Figure 1 to show the structure behind it, and the following internal description of the lower hub 39 will be understood to apply also to the upper hub.

.A sleeve 42, rotatably retained and guided by the cylindrical head 31a of the screw 3l, has secured thereon the pinion 4I previously referred to. A anged bushing 43 is secured in the end of the sleeve 42 and rotatably supports a pin 44 having an exterior flange and a splined driving nose 46, shown in end view in Fig. 7. A compression spring 41, disposed between the bushing 43 and a cross pin 41a near the end of the pin 44, urges the flange 45 against a washer 48 between the flange 45 and the bushing 43 in frictional driving engagement.

The splined driving noses 46 and 49 of the lower and upper driving hubs 39 and 38 are adapted to respectively engage the splined interiors of the hollow pivots v25 and I8 of the lower and upper lm reels. 'Ihe reels Il: and 24 are thus adapted to be rotated by the hubs 38 and 38, respectively, the hollow pivots at the same time serving as pilots or bearing supports for the hubs.

A large boss 50 on the wall I3 has journalled therein a sleeve 5I. Exterior and interior collars 52`and 53 secured to the sleeve 5I retain it in place longitudinally. A shaft 54, rotatably and slidably fitted in the sleeve 5I has secured to its outery end a crank member 55, provided with an internal taper 56 adapted to engage the ta.- pered end 5l of the sleeve 5I. The member 55 carries a crank handle 58, and the hub 59 of the member 55 is shaped as a knob for making fine adjustments in a manner hereinafter described.

A small driving gear e@ is secured on a pilot Si formed on the inner end of the shaft 5d, and a second driving gear 62 of relatively large diameter is fastened on the inner end of the sleeve 5i. Carrier plates 63 and 65, rotatably mounted on the sleeve Si and pilot 6i, respectively, are .fastened together by upper and lower spacer pins 65 and 66, the latter shown in Figures' 2 and 3. Wide faced pinions 61 and 6B are rotatably mounted on the spacer pins 55 and t6, respectively, and arepermanently in mesh with the large driving gear 62.'

Outer transfer pinions 6@ and 1li, also in mesh with the wide faced pinions t? and G8,are rotatably mounted on headed pins 1i and 12 secured to the inner carrier plate ed. Inner transfer pinions .13 and 1S, similarly rotatably mounted on the plate Sil, are in mesh with the outer transfer pinions 69 and iii, respectively, and are adapted to mesh with the small driving gear BU when the shaft 5d is drawn outward, as shown in Figure 4.

A leaf lspring 15, Figurel, is disposed between the inner carrier plate Eil and the large driving gear 62, urging the two apart and creating alight friction which tends to revolve the carrier when the gear 62 is revolved. 'I'he spring 15 is prevented from turning on the carrier plate 63 by loosely fitting pins 1t.

The pinions lil and li on the driving hubs 38 and 39 are disposed in the same plane as the pinions all and vB8 and adapted to selectively mesh with them.

vIn operation, the carrier plates are swung counter-clockwise, as shown in Figure 2, the pinion 68 moves into mesh with the pinion di. Similarly, ii the plates are swung clockwise, as shown in Figure 3, the pinion 51 engages the pinion dil. When the crank member 55 is in engagement with the tapered end 51 of the sleeve 5l, .as shown in Figure l, and the crank is revolved to turn the sleeve 5i and large gear 62 counter-clockwise as in Figure 3, the friction of the spring 15 causes the carrier plates and their entire gear assembly to swing counter-clockwise as a unit until the pinion meshes with the -reel 2t to wind the lm 31 thereon while drawing the latter from the upmr reel 1, which is revolved by the lm.

Revolving the crank in the reverse direction swings the carrier clockwise as shown in Fig. 3, until it is restrained -by a secondadjustable stop 18, the wide faced pinion 58 having released the.

pinion M, while the pinion 61 has engaged the pinion 4B on the upper drive hub 38, after which continued rotation of the crank causes the device to drive the upper lm reel i1 in the manner already described, but in the reverse direction. By this means the iilm is` rewound on the upper reel from the lower reel which is in turn revolved by the lm.

From theforegoing description it is evident that a rotation of the handle in one direction aosaece drives the meer ree1 to wind the mm thereon,

While reverse rotation of the crank automatically shifts the drive to the other reel and draws the film in the reverse direction. The large radial spacing of the pinions 51 'and 5S and the small circumferential movement of the carrier necessary to eiect a change of driving mesh reduces the lost motion during reversal to a minimum, which is substantially unnotlceable to the operator at the short radius of the crank handle 58.

The large diameter of the driving gear (B2 with respect to the4 pinions Il@ and il results in a rapid drive of the lm `reels relative to the speed of the crank.' When the crank member 55 is pulled out, as shown in Fig. 4, thereby releasing the taper 56 from the tapered end 51 of the sleeve 5i, the small driving gear t@ is drawn into mesh with the inner transfer pinions 13 and 16. Rotation of the `crank member 55 now causes meshing of the wide-faced and hub pin-v ions and driving of the reels in the same manner as described except that the drive takes place through the transfer pinion trains, and due to the small diameter of the driving gear 60, the rotative speed imparted tothe hub pinions and nlm reels is low relative to that of the crank member.

`During the low speed drive operation as described, the large gear B2 is revolved by the. widefaced pinions 51 and 6d, so that the leaf spring 15 is still eiective to hold the device in' driving mesh. The radial spacing of the driving hubs 38 and 39 from the center of the shaft 5&1 may be made slightly larger than that of the pinions 61 and 68, by which arrangement the direction ci the driving torque tends to assist the action o the spring in maintaining the device in mesh.

In the foregoing description it has been shown that. movement of the iilm in either direction is accomplished by driving the reel on which the film is being wound, the other reel being revolved by the unwinding of the ilm from it. The plate spring 2l, Fig. 1, bears against the ends of .the reels and maintains thereon a friction which prevents the unwinding reel from over-running when the winding reel is stopped. The film is thus kept 4taut at all times. The drive at all times takes place through the friction of the springpressed flanges l5 and bushings l2 against the member d8 in the driving hubs. If during operation ofthe device the crank is turned until the film is entirely unwound from either reel, the stoppage of the lm causes the washer tt to slip between the iiange and bushing, thereby preventing the film from being torn loose from the reel or otherwise damaged.

To sum up, the device as described and illustrated provides selectively a drive in opposite di-A rection to two shafts by means of normal rotation of a single crank, comprises means of driving. at a high or low speed ratio, and provides a protective release to prevent injury to a device or element being driven as illustrated in the me of the lm 21. The high and low speed drive is particularly useful in the employment of lms carrying microscopic reproductions of reference data, as indicated at 19 on the lm 21, in which the high speed drive is used to rapidly bring the image of a page to registry-with the aperture 22, after which the low speed drive may be used as a micrometric adjustment to bring a single line of the page or column into accurate registry for projection.

In the modied form of the device shown in Figures and 6, the low speed drive from they small driving gear 80 takes place through a single gear train comprising inner and outer transfer pinions 8l and 82. 'I'he outer transfer pinion 5 drives the upper wide-faced pinion 8,3 directly. The lower wide-faced pinion 84 is driven by the upper pinion 83 through the medium of the large driving gear 85, which is in mesh with .both wide-faced pinions, as previously described.

In the modified form the friction to cause the device to rock as a unit to throw either widefaced pinion into mesh is supplied by a torsion spring 8B wound in a groove 81 in the inner end of the shaft 88. The ends 89 and 90 of the spring 88 are hooked or otherwise secured around the outer carrier plate 9|.

Inaddition to supplying the friction noted, the

y spring 88 exerts a mild pressure urging the shaft 88 outward to the right, Figure 6. This pressure is not sufficient normally to disengage the taper 82 in the crank member 93 from the tapered end 94 of the sleeve 95, but once the taper has been disengaged in order to shift the small gear 8B into driving position, the spring pressure throws the gear into mesh with the pinion 8|, and holds it meshed during operation of the low speed drive.y In other words, the device is held in high speed drive position by the taper, and in low speed drive position by the spring 86, which latter prevents the gears from remaining in neutral or in partial mesh and thereby insures positive operaport, a sleeve rotatable therein, a shaft rotatable in said sleeve, a carrier rockable around said sleeve and shaft, 'a driving gear secured on said sleeve, two pinions rotatably mounted in said carrler and in mesh with said driving gear, an outer transfer gear in 'mesh with one of said pinions, an inner transfer gear. in mesh with said outer transfer gear, a second driving gear secured to said shaft and adapted to mesh with said inner 55`transfer gear, meansto couple said shaft to said sleeve, means to rotate said shaft, said shaft be ing slidable in said sleeve to release said coupling means and to bring said second driving gear into -mesh with said inner transfer gear, a pair of 60 hubs rotatively secured to said support, pinions on said hubs adapted to be circumferentially meshed with said rst two pinions respectively, and means positioned between said carrier and driving gear whereby the motion of said gear is I transmitted to said carrier to rock said carrier' to bring one of said first two pinions into mesh with one of said hub pinions when said shaft is rotated in one direction and to bring the other of said first two pinions into mesh with `said 70 other hub pinion when said shaft is rotated in the other direction whereby said hubs may be selectively driven in opposite directions. .2. In a driving device, in combination, a pair of rotatable hubs-.pinions on said hubs, a drive 75 shaft, a Acarrier rockable around said shaft, a

1. In a. driving device, in combination, a 'supf second pair of pinions rotatably carried by said carrier and adapted to be circumferentially meshed with said hub pinions, means. operative between said shaft and said second pinions to drive said second pinions, and means to rock said carrier to individually bring said second pinions respectively into mesh with said hub pinions whereby the rocking of said carrier may be stopped and whereby said hubs may be individually driven in opposite directions,

3. In a device, in combination, a pair of rotatable hubs, pinions on said hubs, a drive shaft, a carrier rockable around said shaft, a second pair of pinions rotatably carried by said carrier and adapted to be circumferentially meshed with said hub pinions, means including two-speed gearing operative between said shaft and said second pinions to drive saidI secondpinions, and means to rock said carrier to selectively bring said second pinions into mesh with said hub pinions whereby the rocking of said carrier may be stopped and whereby said hubs may be selectively driven in opposite directions.

4. In a driving device in combination, a pair of rotary hubs carrying members adapted to positively engage rotary elements to be driven by said device, pinions on said hubs, a driving shaft, gear means connected to said shaft including a pinion adapted to mesh with and drive one of said hub pinions only when said shaft is rotated in one direction and said gear means including a second pinion adapted to mesh with and drive the other of said hub pinions only when said shaft is revolved in the opposite direction, and torque-limiting means included in said hubs.

5. A device as claimed in claim 4 wherein said gear means includes a two-ratio selective driving mechanism. y

6. A device as claimed in claim 4 wherein said gear means includes a two-ratio selective driving mechanism and means to hold said mechanism in either driving ratio.

7. In combination, two-rotary members, two members to be driven thereby, means to couple said rotary members to said second members, a driving member, gear means operable by said driving member to engage and drive one of said rotary members when said driving member is r0- tated in one direction and to engage and drive said other rotary member when said driving memberis rotated in the opposite direction, said engagements being eected solely by initial movements of said driving member in said respective directions.

8. The invention according to claim 7 wherein said coupling means includes means to limit the torque which may be transmitted thereby to said members to be driven.

9. In combination, a support, a sleeve rotatable in said support and having a tapered portion, a shaft rotatable in said sleeve, a driving gear on said sleeve, driven gears operable by said gear, a gear train engaging said driven gears, a second driving gear on said shaft, said shaft being slidable in said sleeve,` a driving member on said shaft and comprising a tapered portion adapted to engage said first tapered portion whereby said sleeve and shaft may be coupled together, and resilient means to slide said shaft to bring said second driving gear into engagement with said gear train when said tapered portions are disengaged.

10. In a driving device, in combination, a support, a sleeve rotatable therein, a shaft rotatable in said sleeve, a carrier rockable around said sleeve and shaft, a driving gear secured on said sleeve,

two pinions rotatably mounted in said carrier and in mesh .with said driving gear, an outer transfer gear in mesh with one of said pinions,an inner transferl gear in mesh with said outer transfer gear, a second driving gear secured to said shaft and adapted to mesh with said inner transfer gear,

means to couple said shaft to said sleeve, means to rotate said shaft, said shaft being slidable in said sleeve to release said coupling means and to` bring said second driving gear into mesh with said inner transfer gear, a. pair of hubs rotatively seother direction, whereby said hubs may be seleca 10 tively driven in opposite directions.

VERNEUR. E. PRATT. 

